A conventional watering nozzle 80 is shown in FIGS. 4 and 5, and generally includes a barrel which has a first passage 812 defined therein and a handle 81 is connected to the barrel and a second passage 811 is defined through the handle 81. The first and second passages 812, 811 are in communication with each other. An operation rod 82 is movably inserted into the first passage 812 from a rear end of the barrel and a spring 813 is mounted onto the operation rod 82. A collar 831 is received in the first passage 812 and has a central hole in which an insertion 821 on an end of the operation rod 82 is removably inserted. A nozzle member 83 is connected to the front end of the barrel and a rotatable member 84 is rotatably mounted onto the nozzle member 83. An operation bar 85 is pivotably connected to the handle 81 and has one end pivotably connected to the operation rod 82. When operating the operation bar 85, the operation rod 82 is pulled and the insertion 821 is removed from the central hole of the collar 831, so that water flows through the from the second passage 811, enters into the first passage 812, flows through the central hole of the collar 831 and flows out from a through hole in the nozzle member 83. The user may rotate the rotatable member 84 to adjust the size of the gap between the opening 841 of the rotatable member 84 and the distal end of the nozzle member 83 to adjust the pattern of the water beam. When releasing the operation bar 85, the operation rod 82 is moved to insert the insertion 821 in the central hole of the collar 831 to seal the central hole so that the water cannot flow out from the opening 841 of the rotatable member 84. However, the water volume that released from the opening 841 of the rotatable member 84 is unknown and the water volume is crucial for some situations such when watering specific plants like orchids.
The present invention intends to provide a watering nozzle with a water volume display device which displays the volume of water that goes out from the watering nozzle.